@Repository
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th=
        "http://www.thymeleaf.org" lang="en">
<head th:replace="fragments/header :: head">
</head>
<body>
<div th:replace="fragments/header :: navbar"></div>
<div class="container">
    <h3 class="text-center">欢迎使用 Litehelf！</h3>
    <div class="row justify-content-center">
        <div class="col-6">
            <div class="alert alert-danger" th:if="${param.error}">
                <strong> 无效用户名和密码</strong>
            </div>
            <form class="form" role="form" th:action="@{/login}" method="post">
                <div class="form-group">
                    <label for="username">用户名</label>
                    <input type="text" class="form-control" name="username"
                           id="username" placeholder="用户名" required>
                </div>
                <div class="form-group">
                    <label for="password">密码</label>
                    <input type="password" class="form-control" name=
                            "password"
                           id="password" placeholder="密码" required>
                </div>
                <div class = "col-12 text-right">
                    <button type="submit" class="btn btn-primary">登录
                    </button>
                    <a class="btn btn-primary" th:href="@{/registration}">
                        注册</a>
                </div>
            </form>
            <p></p>
        </div>
    </div>
    <div class="row justify-content-center">
        <div class="col-6">
            <div class="alert alert-warning">
                <span> 还未注册用户吗？ 请先注册:)</span>
            </div>
        </div>
    </div>
</div>
</body>